Using lapply to source multiple R scripts in sub-directories - r

Question

These are the folders in my directory
128 128-1-32 16384 16384-1-36 4096-1 512 512-1-65 65536-1
128-1 128tbw1 16384-1 4096 4096-1-36 512-1 65536
Each of them has a7.R code that loads files from each folder and creates images.I want my script to enter each of the folders then
source('a7.R')
then exit that folder and repeat the process for all the folders.I am doing this now manually and it is really boring.Is this possible with R?
I have tried solution like this
#!/usr/bin/Rscript
lapply(list.files(full.names=TRUE, recursive = TRUE, pattern = "^a7\\.R$"), source)
milenko#milenko-desktop:~/jbirp/mt07$ Rscript s.R
list()
The coffeinejunky's solution is not working
#!/usr/bin/Rscript
foo <- function(directory) { setwd(directory); source(a7.R) }
do.call("foo", list(directory= 128 128-1-32 16384 16384-1-36 4096-1 512 512-1-65 65536-1 128-1 128tbw1 16384-1 4096 4096-1-36 512-1 65536))
source('n.R')
Error in source("n.R") : n.R:2:33: unexpected numeric constant
1: foo <- function(directory) { setwd(directory); source(a7.R) }
2: do.call("foo", c(directory= 128 128
If i change list like this
do.call("foo", list(directory= "./128" "./128-1" "./128-1-32" "./128tbw1" "./16384" "./16384-1" "./16384-1-36" "./4096" "./4096-1" "./4096-1-36" "./512" "./512-1" "./512-1-65" "./65536" "./65536-1"))
I got
Error in source("n.R") : n.R:2:40: unexpected string constant
1: foo <- function(directory) { setwd(directory); source(a7.R) }
2: do.call("foo", list(directory= "./128" "./128-1"
^
This is what I got when I list path
> list.dirs(path = ".", full.names = TRUE)
[1] "." "./128" "./128-1" "./128-1-32" "./128tbw1"
[6] "./16384" "./16384-1" "./16384-1-36" "./4096" "./4096-1"
[11] "./4096-1-36" "./512" "./512-1" "./512-1-65" "./65536"
[16] "./65536-1"
I need to change directory multiple times and perform the same operation in each of them.Is lapply good for this or not?

Answer 1

The following should work:
directories <- list.dirs(path=".", full.names = T)
# you need to make sure this contains the relevant directories
# otherwise you need to remove irrelevant directories
foo <- function(x) {
old <- setwd(x) # this stores the old directory and changes into the new one
source("a7.R")
setwd(old)
}
lapply(directories, foo)
Alternatively,
for(folder in directories) foo(folder)

Answer 2

This will source every a7.R file with the working directory temporarily set to the sourced file's folder.
a7files <- list.files(full.names=TRUE, recursive = TRUE, pattern = "^a7\\.R$")
sapply(a7files, source, chdir = TRUE)
From ?source
chdir logical; if TRUE and file is a pathname, the R working directory is temporarily changed to the directory containing file for evaluating.